Electric circuit breaker



May 13, 1952 3, G 2,596,506

a ELEQTRIC CIRCUIT BREAKER Filed Dec. 21, 1950 Z5 2 ZAJE'WI 1w by 5mum/0m 5% 8 0 /f 25 4 27 f) v Z6 z Ihventor:

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Patented May 13, 1952 UNITED STATES PATENT OFFICE.

ELECTRIC CIRCUIT BREAKER Robert G. Page, New Britain,- Conm, assignor,by

mesneassignmentato General Electric Company, a corporation of New YorkApplication December 21, 1950; Serial No; 201.943 1 6 Claims.- (Cl.200-166) Mydnvention relates to circuitwbreaker units andpartieularly tothecontacts of arunit which isrdesigned to'be detachablymounted on "apanel board or the like.

One object of the invention is to providefor a.

resiliently supported contact.

A special object isto providefor a contact structure adapted to be'detachably supported on a fixed base.

One objectis to providea'compact and effec tive'structure.

Another object is: to provide an economical structure consisting of fewand simple parts.

Another 'object is to provide a structure which is easy; to assemble.

Another object is to provide astructure having good arc-interruptingability.

Another object is to provide a structure which is highly resistant tomechanical shock.

Another object is to guard the resiliently mounted contact structurefrom arcing.

Fig. 1 is a side view and partial section showing the contactsofacircuit breaker embodying myinventicn as applied to a panel board orother support.

Fig. 2 is a sectional view on a larger scale, the section being-taken onthe planeof the line 2-2 of Fig. 1.

Fig. Bis a perspective view'showing parts of the contacts of Figs. 1and'2.

Fig. 4 is'a perspective view of a reinforcing spring.

Fig. 5 is a side view showing the rock shaft, the switch arm being shownin section.

Fig. 6 is a perspective view of one end of the rock shaft.

Fig. '7 is a perspective view of the switch arm.

The insulating support I, constituting a part of a panel board or othersupport, has a circuit terminal 2 with a projecting terminal prong orblade 3.

The circuit breaker has an insulating base, a part 4 of which is shownin Figs. 1 and 2. The relatively stationary jaws 5, 6 and I are formedas a part of the terminal structure 3 which is secured to the base 4 bya screw 9. The jaws are preferably formed of resilient material so thatthey will clamp the opposite sides of the panel blade 3 when the circuitbreaker is mounted on the panel.

An insulating cover plate I0 is secured to the terminal structure 8 bysuitable means such as the rivets H. The contact member I2 is in theform of a cup which is mounted in a passage l3 in. plate I0 and has aflange portion l4 beneath the plate Ill. The contact surface may be iii)2. separately formed of suitable material and attached to or made a partof the contact cup 12-. A spring I6 is interposed between the insulatingsupport lland the cup I2.- The contact cup is electrically connected tothe structure 8 by flexible conductors I 8. IS.

The cover plate Ill of insulating material guards all of the contactstructureexcept the contact l5-lwhich, of course, must be exposed.

The contact 20 iscarried by the arm 2| and coacts withthe relativelystationary contact member. The lever 21 constitutes the movable switchmember of the circuit breaker and is mounted on a shaft 22 of the rockermechanism (not shown).

The shaft 22 may be enclosed-in an insulating sleeve 23. The switch arm.2| has a collar 24 drawn from. the metal'of the arm to receive sleeve23. The extension 25 is secured to the shaft 22 by a set screw 26 andconstitutes the means for transmitting motion from the circuit breakermechanism (not shown);

The switch arm 2! is connected electrically to a terminal of "thecircuit breaker (not shown) by means .of afiexible conductor 27. The useof an edgewi'semounted blanked switch arm permits close assembly ofadjacent parts.

The contact jaws 5, E and I may be reinforced by a spring clamp member28 having a crosspiece 29 compressing against the spring jaw 5 andhaving end members 30, 3S pressing against the back of the jaws 6 and i.

From the foregoing it will be seen that the con tact $5 is pressedtoward the contact 29 by the action of the spring it, but the movementof the contact member i2 is limited by the engagement of the flange isbeneath the insulating plate it It will be understood that the operatingand tripping mechanism and overload devices of a circuit breaker willfunction in a conventional manner.

The spring-pressed contact member 12 acts as a buffer for the switch armand holds the circuit closed in case the switch arm should become loose.

I claim:

1. In an electrical circuit breaker, a lower fixed terminal blade, anupper movable switch arm and a contact unit between said blade andswitch arm including a body portion of strip metal having downwardlyextending spaced contact jaws formed on one end thereof for engagingsaid terminal blade and having an oiiset portion formed on the oppositeend, an insulatin plate secured to said offset end and extendingparallel to said body portion in spaced relation, a movable contactmember guarded by said insulating plate, a flexible conductor connectingsaid body portion and said movable contact member, and a spiral springbetween said body portion and said movable contact member for urgingsaid movable contact member into engagement with said upper switch arm.

2. In an electrical circuit breaker, a lower fixed terminal blade, anupper movable switch arm and a contact unit between said blade and saidswitch arm including a body portion having a plurality of spacedresilient contact jaws depending from one end thereof for engaging theterminal blade, an insulating plate mounted on said body portion, anupwardly extending movable contact member carried by said insulatingplate and spaced from said contact jaws for engaging said switch arm, aflexible conductor connecting said body portion and contact member, andspring means in the space between said body portion and said movablecontact member for urging the latter into engagement with said switcharm.

3. In an electrical circuit breaker, a lower fixed terminal blade, anupper movable contact member and a contact unit between said blade andcontact member including a body portion having a plurality of spacedresilient contact jaws depending from one end thereof for engaging theterminal blade, an insulating plate mounted on said body portion andhaving an opening, an upwardly extending movable contact memberextending through the openin in said insulating plate for engaging saidupper movable contact member, a flexible conductor connecting said bodyportion and said contact member, and

spring means for urging said upwardly extending contact member intoengagement with said upper movable contact member.

4. As an article of manufacture, an electrical contact unit for use witha circuit breaker, comprising a fiat body portion of strip metal, a pairof parallel resilient jaw members depending from one end of said bodyportion and another jaw member offset from said pair for engaging aswitch blade, the opposite end of said body portion being offset, aninsulating plate secured at one end to said offset end of the bodyportion and extendin along the remainder of the body portion in spacedrelation, a switch member movably supported at the other free end of theinsulating plate, a conductor connecting said body portion and saidswitch member, a spiral spring in the space between the body portion andinsulating plate for urging said switch member upwardly, and a springencircling said jaws for urging the jaws toward each other in a clampingaction.

5. As an article of manufacture, an electrical contact unit for use witha circuit breaker, comprising a body portion, spaced resilient contactjaws depending from one end of said body portion for engaging a terminalblade, a movable contact member supported on the body portion and spacedfrom the contact jaws, a flexible conductor connecting said body portionand contact member, and spring means in the space between said jaws andsaid movable contact member for urging the latter into engagement with aswitch arm.

6. As an article of manufacture, an electrical contact structure, foruse with a circuit breaker, comprising a flat body portion of stripmetal having a pair of spaced resilient parallel jaws depending from oneend thereof and having another resilient jaw between said pair andoffset therefrom for receiving a blade between said jaws, said bodyportion having an offset portion at its other end, a flat insulatingplate secured at one end to said ofiset portion and extending over saidbody portion in spaced relation, a cup-shaped contact member movablymounted in the other end of said insulating plate for engaging a switcharm, a flexible conductor connecting said body portion and contactmember, and a spiral spring having one end seated on the body portionand its other end seated in said cup-shaped contact member for urgingsaid cup-shaped contact member outwardly of the insulating plate supportinto engagement with the switch arm.

ROBERT G. PAGE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,922,648 Watts Aug. 15, 19332,164,200 Douglas June 27, 1939

